Golden Ages and how they stack question

I believe that Golden Ages are better when you combine them than having them separately.

I believe that if you get "Golden Age (X)" you only get most of the Golden Age bonuses for X-1 turns. In particular, I have found that on what should be the last turn, Golden Age (1), you don't seem to get the production bonus for that turn.

One tricky thing with Persia is that on Golden Age (X) your units don't get the extra movement point (they have 2/3) but right after your Golden Age ends, they have one turn where they have the extra movement point.

In any case, since I often lose the last year of a Golden Age, I prefer to combine Golden Ages, since that essentially gives me one extra turn.